Acetylcholine binding protein



Acetylcholine binding protein (AChBP) is secreted by snails into cholinergic synapses, where it modulates transmission by binding acetylcholine (ACh). Sequence alignment revealed high similarity to the extracellular domains of the ligand-binding subunits of the nicotinic acetylcholine receptor (nAChR). The crystal structure of the AChBP homopentamer indeed provides a valuable model for identifying the nature of the ligand-binding domains and of the subunit interfaces of the nAChR. Furthermore, crystal structures of complexes of AChBP with various agonists and antagonists have provided detailed insight into the neurotransmitter binding site of nAChRs. The images on the left and right correspond to one representative AChBP structure, i.e. the Acetylcholine binding protein from Aplysia  californica (2byn).

3D Structures of Acetylcholine binding protein
Update June 2011

AChBP - Apo proteins
2w8e, 2byn, 2y7y - Aplysia californica (AcAChBP)

1ux2, 1i9b - Lymnaea stagnalis (LsAChBP)

2bj0 - Bulinus truncatus

AChBP + marine biotoxins
2wzy - AcAChBP + 13-desmethyl spirolide C

2x00 - AcAChBP + gymnodimine A

AChBP + partial agonists; Activate the receptor with partial efficacy
2wn9 - AcAChBP + 4-OH-DMXBA

2wnc - AcAChBP + tropisetron

2wnj - AcAChBP + DMXBA

2wnl - AcAChBP + anabaseine

AChBP+ions; Mimicking the ion conductance of the receptor
3gua - AcAChBP + sulfate

AChBP+ neonicotinoids; Insecticides with lower affinity to mammals
3c79 - AcAChBP + imidacloprid

2zju - LsAChBP + imidacloprid

3c84 - AcAChBP + thiacloprid

2zjv - LsAChBP+clothianidin

AChBP+ non-competitive inhibitors which bind at site different than the active site and reduce the rate of receptor reaction
2pjz - AcAChBP+cocaine

2ph9 - AcAChBP+galanthamine

2w8f, 2w8g - AcAChBP + in silico compounds

AChBP+ peptide inhibitors
2c9t, 2byp, 2br8 - AcAChBP+conotoxin IMI

2uz6 – A-AChBP fragment + α-conotoxin 1yi5 - AcAChBP+cobratoxin

AChBP+ nicotinic agonists enhance the action of the nAChR
2pgz - AcAChBP+cocaine

2byr - AcAChBP+methyllycaconitine

2bys - AcAChBP+lobeline

AChBP+ ligand homologs of the ligand acetylcholine
1uv6 - LsAChBP+ carbamylcholine

1uw6 - LsAChBP+nicotine

AChBP+others
2br7 - AcAChBP+ HEPES

Additional Resources
For additional information, see: Alzheimer's Disease